The present invention relates to a method and a device for the contactless optical determination of the 3D position of an object, wherein the determination of the 3D position includes the determination of the 3D position and the 3D orientation of the object and wherein the geometrical characteristics of the object are known.
The automation of production flows plays an increasingly important role in industrial manufacturing. For production lines, which do not allow an exact positioning of the components to be processed, it is especially important to know the complete 3D position of the component, i.e., the 3D position and the 3D orientation in space, in order to be able to grasp and process the component using a robot.
In addition, the determination of the 3D position can be used for calibrating a robot. The geometrical characteristics are thereby arranged in a known manner on the robot arm, or a calibration target is mounted on the robot arm. The robot arm is moved in the lens coverage of a stationarily mounted camera and thereafter the determination of the 3D position of the robot arm is carried out in order to examine and/or recalibrate its position and orientation.
Another application is the determination of the 3D position of components in the installed state. By determining the position of a reference part, for example, it is possible to examine whether the position of installed parts is consistent with the position of the reference part, in order to thus determine incorrectly mounted components.
Nowadays, known devices for determining the 3D position are exclusively multi-camera systems, which involve considerable costs due to the use of two or more cameras. In the context of the use of a single camera, only adjusted 2D methods for grasping components are known so far, i.e., the position and orientation in a plane (3 degrees of freedom) and additionally height information about the height of the component (1 more degree of freedom) are determined. However, using this known method, at most 2½D information is obtained about the position of the component, as a result of which, for example, it is not possible to correctly grasp the component when the latter is in an oblique position.
The calibration of a robot is mostly carried out manually according to the current state of the art, due to the lack of corresponding auxiliary means for setting up all 6 degrees of freedom. The calibration is extremely time-consuming, thus resulting in long maintenance intervals. In addition, the manual calibration methods are, in general, relatively inaccurate.
Nowadays, the determination of the position of a component after its installation can also be carried out using only multi-camera systems. Alternatively, sensory solutions for single measured variables are known, wherein said solutions solve the actual total problem using a multi-sensor evaluation. Such sensory multiple measurements are also time-consuming and are often hardly helpful for the overall assessment of the 3D position.
The object of the present invention is to design and to further improve a method and a device for the contactless optical determination of the 3D position of an object in such a way that it is possible to determine complete 3D information about the object to be studied using simple means and at high measuring speed and measuring accuracy.